Unanswered question

We are facing some challenges while trying to correlate one value.We have a server response below:Name","store":[["","<none>"],["Person:XYZ","Karen Egertson"],["Person:ABC","Robert Farley"]],From here we want to capture value “ABC” with “LB=["Person:” & “RB=","Robert Farley"]],”.But it is taking the first occurrence of the LB and then picking up the value till RB. So the parameter value it is fetching is like XYZ","Karen Egertson"],["Person:ABC and we are not able to find out any unique boundary.Please provide us a complete solution.